In this case, the domal highs that form the exhumed footwall to the faults can be described as oceanic core complexes. The faults seem to continue as the ridge-facing flank of these highs and some may extend over the crest of the high to breakaways beyond. This larger-scale topography is associated with a different style of faulting: the depth images reveal gently dipping (<35°) faults that are rooted in the deep crust and that project to the ridgeward flank of the dome-shaped large basement highs (1–2 km vertical relief). In contrast, the inside corner crust is more rugged, with basement highs rising up to 2 km above the intervening basins. Also observed away from FZs are gently dipping to subhorizontal reflections in the upper crust, which resemble detachment faults.
These faults could be related to the lifting of the lithosphere out of the median valley to the flanking mountains. Away from major fault zones (FZs), most faults are subplanar, dip more than 35°, are associated with moderate basement relief (0.2–1 km relief) and may penetrate to deep crustal levels. The images document the scale and geometry of normal faulting in oceanic crust formed over 25 Myr at a half-spreading rate of less than 10 mm yr −1, and the variation in extensional style with position within the spreading segment. Compared with post-stack time migrations, the images illustrate the improvement resulting from the application of pre-stack depth migration. We present depth images, from portions of profiles that are close to flow-lines, of Cretaceous oceanic crust in the eastern Central Atlantic.